Carmela Negulescu *, A. Ciucu **, V. Magearu ***
* Biochimist drd. Carmela Negulescu, Wyeth Whitehall, București
** Prof. dr. Anton Ciucu, Catedra de Chimie Analitică, Facultatea de Chimie, Universitatea din București
*** Prof. dr. Vasile Magearu, Catedra de Chimie Analitică, Facultatea de Chimie, Universitatea din București
Abstract
An enzymatic sensor for choline was constructed from an oxygen amperometric sensor on whose surface a dialysis membrane containing covalently immobilized cholin-oxidase was set. Immobilization of enzyme on the dialysis membrane surface was achieved with 2,4-dichloro- 6-mehtoxy-s-triazine, a derivative of cyanuric chloride, which unlike others of its mono-substituted derivatives, ensures some advantages. The time of measurements is about 15-20 sec. for the kinetic method of the initial slope, and about one minute for the steady-state method. The sensor respond linearly to choline in the concentration range 10-2 – 10-4 moles/I (kinetic method) and 5 x 10-3- 10-3 moles/I (steady-state method).